The proposed conference will be the second in a new series of Gordon Conferences on Molecular Membrane Biology; that is, molecular aspects of cell biology that concern membranes. The focus will be on problems of compartmentation and specificity in cellular membrane organization. Mechanistic studies of specific molecules are emphasized. The interface between molecules and the higher aspects of cellular organization is already an important and rapidly growing inter-disciplinary area; this conference will help catalyze its further development by bringing together many of the key investigators in a closed, informal setting under the unique auspices of the Gordon Conferences. Speakers are being chosen on the basis of their important current research and also because the approach taken is one that is helping, or will ultimately help, us understand the specificity of cellular organization in terms of the action of individual molecules. Topics to be covered include: high-resolution diffraction studies of membrane proteins; mechanisms in bilayer and membrane protein assembly; enzymology and genetics of protein translocation, sorting, and intracellular transport; molecular organization in the Golgi; coated vesicles; origin of epithelial cell surface polarity; specificity of membrane fusion; biochemistry of specific receptors used in the endocytic cycle; cell locomotion.